21073471 has 2 divisors, whose sum is σ = 21073472. Its totient is φ = 21073470.

The previous prime is 21073469. The next prime is 21073511. The reversal of 21073471 is 17437012.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21073471 - 2¹ = 21073469 is a prime.

It is a super-3 number, since 3×21073471³ (a number of 23 digits) contains 333 as substring.

Together with 21073469, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21073411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10536735 + 10536736.

It is an arithmetic number, because the mean of its divisors is an integer number (10536736).

Almost surely, 2^21073471 is an apocalyptic number.

21073471 is a deficient number, since it is larger than the sum of its proper divisors (1).

21073471 is an equidigital number, since it uses as much as digits as its factorization.

21073471 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1176, while the sum is 25.

The square root of 21073471 is about 4590.5850389683. The cubic root of 21073471 is about 276.2137906309.

The spelling of 21073471 in words is "twenty-one million, seventy-three thousand, four hundred seventy-one".